Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)
20091231
Simrad em3002d Backscatter imagery of Ni'ihau Island, Hawaii, USA
digital data
http://www.soest.hawaii.edu/pibhmc/pibhmc_mhi_nii_backscat.htm
Backscatter imagery extracted from gridded bathymetry of Ni'ihau Island, Hawaii, USA.
These data provide almost complete coverage between 0 and 100 meters. The backscatter dataset includes
Simrad EM3002d, Simrad EM300 and Reson 8101 data. The sonars frequencies are 300 kHz,30kHz and 240 kHz respectively and are
processed and gridded separately. Because of the similar sonar frequencies the data can be mosaicked nearly
seamlessly using GIS software.
This metadata is for the Simrad em3002d backscatter data only.
The geotiffs of backscatter imagery were created using data gathered from multibeam
soundings for use as a planning and reference document. The data are also being used
for benthic habitat mapping, for locating Essential Fish Habitat, and for studying
geologic features of the area. Refer to supplemental information for description of
instrument and survey.
Data were collected aboard the NOAA Ship Hi'ialakai, a 218' United States
National Oceanographic and Atmospheric Agency research ship. The NOAA
Ship Hiialakai's survey sensors include a 30 kHz Simrad EM300 sonar
and a 300 kHz Simrad EM3002d sonar, which provide bathymetry and
backscatter data, a TSS/Applanix POS/MV Model 320, which measures position,
velocity, attitude and heading, and a Seabird SBE 9/11 plus CTD used to
measure sound velocity profiles.
Specific equipment configurations are documented in cruise metadata from
cruises HI0504.
20050613
20050708
ground condition
Complete
As needed
-160.292237
-160.017010
22.059616
21.729768
CoRIS Theme Thesaurus
EARTH SCIENCE > Oceans > Bathymetry/Seafloor Topography > Backscatter
CoRIS Discovery Thesaurus
Geographic Information > Backscatter
None
Acoustic Imagery
Backscatter
ISO 19115 Topic Category
geoscientificInformation
008
imageryBaseMapsEarthCover
010
None
Niihau
Hawaii
Main Hawaiian Islands
United States of America
CoRIS Place Thesaurus
COUNTRY/TERRITORY > United States of America > Hawaii > Kauai > Niihau Island (21N160W0001)
OCEAN BASIN > Pacific Ocean > Central Pacific Ocean > Hawaiian Islands > Niihau Island > Niihau Island (21N160W0001)
CoRIS Region
MHI
None
These data are not to be used for navigation purposes.
Please acknowledge NOAA (Office of Ocean Exploration and the
Pacific Islands Fisheries Science Center) and the Joint Institute for
Marine and Atmospheric Research (JIMAR) University of Hawaii as the
sources of this information.
Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)
Frances Lichowski
mailing and physical address
NOAA IRCNMFS/PIFSC/CRED1845 WASP Blvd., Building 176
Honolulu
HI
96818808 725-5360808 725-5429
nmfs.pic.credinfo@noaa.gov
e-mail preferred
http://www.soest.hawaii.edu/pibhmc/MHI_images/NII_bs_em3002_440.jpg
Backscatter, Acoustic Imagery
JPEG
Benthic Habitat Mapping Group, Coral Reef Ecosystem Division
(CRED), Pacific Islands Fisheries Science Center (PIFSC), NOAA and the Joint
Institute for Marine and Atmospheric Research (JIMAR) are the sources of
this information.
Not applicable
Unclassified
Not applicable
Data are collected for resource management
and research purposes and are tested for internal consistency; however,
no effort is made to compare these data to external references or to
other published data.
These data are believed to be logically consistent
though no tests were performed
Complete
Horizontal positioning system: GPS (SPS)
Horizontal position accuracy: 25 meters
1m
Range resolution of sonar ~1.25 cm
Raw sounding resolution: Variable
Vertical accuracy of gridded product: 1% of water depth
Science Applications International Corporation's (SAIC) ISS-2000 acquires,
processes and records data, provides survey control and underway quality
control displays. SAIC's SABER processing software is used to process the
raw soundings, analyze the results, manually edit the sounding data to remove
outliers and derive average gridded data values. Additional data acquisition
and processing information can be found in the metadata for cruises HI0504.
Hawaii Mapping Research Group (HMRG) processing software was then used to
extract values of acoustic intensity from the soundings. HMRG is an organization
of scientists, engineers and technicians whose mission is to design, build,
and operate tools for mapping the seafloor. HMRG is a group within the School
of Ocean and Earth Science and Technology at the University of Hawaii at Manoa.
The gsf2bs program (July, 2005) converts the swath bathymetry ping records contained
within a GSF (Generic Sensor Format) version 2.02 dataset into bs file format. This
is done as follows: (i) position each beam's bottom detect intensity sample at the
across-track location of that beam's bathymetry value; (ii) assuming a flat bottom
in the near neighborhood of the beam, compute across-track distances for all of the
beam's remaining intensity samples based on their temporal relation to the bottom
detect sample and the computed average sound velocity for that beam as derived from
its range and travel time; (iii) after all of the intensity samples from all beams
of a ping have been located in across-track distance, fill the gaps between them as
necessary by interpolation.
The conversion described above is necessary in order to run HMRG backscatter processing
operations on the data, such as filtering to remove noise, and to create netCDF grids,
raster images and GeoTIFF's. For more information on the backscatter processing technique
see <http://www.soest.hawaii.edu/pibhmc>.
The backscatter mosaic served here was created using the Mosaic to New Raster in the ArcMap
Version 9.3 Toolbox and exported from ArcGIS as a GeoTIFF file to create images containing
the em3002d backscatter data from the 2005 and 2006 surveys.
Software_Used:
SAIC ISS-2000 Acquisition Software, v 3.4 (20030610)
SAIC SABER Processing Software, v 2.0.2 (20030610)
Hawaii Mapping Research Group (HMRG) Processing Software
GMT Generic Mapping Tools, v 4.4 (20090216)
MB System, v 5.1.2beta05
ESRI ArcMap 9.x
20091208
Raster
Grid Cell
36305
28163
1
Universal Transverse Mercator
4
0.9996
-159
0
500000
0
Row and Column
1
1
meters
D_WGS_1984
WGS_1984
6378137.000000
298.257224
mean lower low water
0.01
meters
Attribute Values
Backscatter data within a GSF file are arranged as small sequences of intensity
values, one sequence per beam per ping. The intensity values represent the
amplitude of echo returns to the sensor and can be related to seabed hardness
and roughness.
none
Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)
Frances Lichowski
mailing and physical address
NOAA IRCNMFS/PIFSC/CRED1845 WASP Blvd., Building 176
Honolulu
HI
96818808 725-5360808 725-5429
nmfs.pic.credinfo@noaa.gov
e-mail preferred
Downloadable Data
These data are not to be used for navigational purposes.
NOAA makes no warranty regarding these data, expressed or implied, nor
does the fact of distribution constitute such a warranty. NOAA cannot
assume liability for any damages caused by any errors or omissions in
these data, nor as a result of the failure of these data to function
on a particular system.
GeoTIFF, .tif
TIFF is a format for storage, transfer, display, and printing of raster images. The TIFF file
structure allows both the ta and the image data to be encoded into the same file. GeoTIFF
refers to a TIFF file that has geographic data embedded as tags within the TIFF file.
The geographic data can be used to position the image in the correct location and geometry
on the screen of a geographic information display. Any GIS, CAD, Image Processing,
Desktop Mapping and other types of systems using geographic images can read any GeoTiff file.
More specifically, files of this type can be added to ArcInfo and ArcView 8.x or higher and may
be viewed in the Table of Contents as a new raster layer. Image visualization software that does
not use geography as a basis for image placement can view a GeoTIFF image as if there were no
geographic information in the TIFF file. For example, GeoTIFF files can be viewed using Windows
Picture and Fax viewer.The GeoTIFF format is public domain, non-proprietary.
none
http://www.soest.hawaii.edu/pibhmc/pibhmc_mhi_nii_backscat.htm
None
20140312
20100108
Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)
Frances Lichowski
mailing and physical address
NOAA IRCNMFS/PIFSC/CRED1845 WASP Blvd., Building 176
Honolulu
HI
96818808 725-5360808 725-5429
nmfs.pic.credinfo@noaa.gov
e-mail preferred
FGDC Content Standards for Digital Geospatial Metadata
FGDC-STD-001-1998
Local Time
None
None
20100108032435
None
20050613
20050708
http://www.coris.noaa.gov/metadata/records/html/nii_em3002d_backscatter_tif.html
4414